Fasciolariidae (Gastropoda: Neogastropoda) of French Guiana and nearby regions, with descriptions of two new species and comments on marine zoogeography of northeastern South AmericaAuthorLyons, William G.AuthorSnyder, Martin AverytextZootaxa20192019-04-1245852239268journal articlehttps://doi.org/10.11646/zootaxa.4585.2.20d5b0561-a16b-4ed8-a9e8-2b71606303391175-53262637300882D13C5-D921-43B3-9847-4B3925EBB671Polygona lactea
(
Matthews-Cascon, Matthews & Rocha, 1991
)
(
Figures 29–38
)
Latirus lacteum
Matthews-Cascon
et al
., 1991
: 1
–6, figs. 1–4;
Snyder, 2003
: 123
;
Mallard & Robin, 2005
: 18
(
Brazil
);
Pimenta
et al
., 2014
: 69
, 90, figs. 19 (
holotype
figured in two views).
Polygona lactea
:
Vermeij & Snyder, 2006
: 418
–420, fig. 3R.
Types.Holotype
: dd,
27 mm
, off
Pará
,
Brazil
,
01°32’05”N
,
47°24’05”W
,
63 m
,
MNRJ 6201
.
Paratypes
: 2-dd, 18 and
32 mm
, CMPHRM 688B and 1031B.
Material examined. French Guiana
—2-dd, 25.5 and
29.5 mm
,
GUYANE
sta. CP 4352,
05°13.9’N
,
51°41.7’W
,
60 m
,
28 Jul 2014
.
Remarks.Latirus lacteum
Matthews-Cascon
et al
., 1991
, was introduced for five specimens dredged from coralline algae substrates off Pará and
Amapá
,
Brazil
. The description and figures resemble some specimens of
P. bernadensis
from
French Guiana
. We could not obtain specimens for comparison but obtained photographs of the
holotype
(
Figs. 29–30
) and two
paratypes
(
Figs. 31–34
). The
paratypes
are long-dead shells bearing polychaete tubes, foraminifera, and other encrustations, but the
holotype
, a shiny white shell, is fresh and in good condition except for an eroded protoconch.
Specimens we include here as
P
.
lactea
are two empty white shells with broken lips and drill holes (
Figs. 35–38
); white seems to have been their original color and not a result of fading. Protoconch and teleoconch morphologies of the shells resemble those of
P
.
bernadensis
but the protoconchs are slightly smaller and the revolving cords of the spire are narrower than those of the latter species; many cords of
P
.
lactea
are separated by single, finer threads in their interspaces. The net effect is of a shell that more resembles the original figures of
P
.
lactea
than they do shells of
P
.
bernadensis
.
Although
P. lactea
was listed by
Mallard and Robin (2005)
, it was not included in the compendium by
Mallard and Robin (2017)
. Very few specimens are known, and the original specimens seem to have been immature and in less than optimal condition. Perhaps fresher mature specimens could enable better understanding of this poorly known species.